Granted Patent B2

US 8,361,027 · App. 13/184,473 · Granted Jan 29, 2013

Abstract

Claims (31)

1. A drug delivery device comprising:

(a) a housing containing a drug reservoir;

(b) a slidable piston operable to expel drug from the drug reservoir;

(c) a mechanism in communication with the piston, the mechanism being operable to undergo incremental advancement and thereby drive the drug from the reservoir in a series of fixed increments, wherein the mechanism comprises a rigid ratchet element having regularly spaced formations on a surface thereof;

(d) a member operatively associated with the mechanism to cause the incremental advancement of the mechanism as the member moves in a first direction;

(e) a pawl carried on the member, the pawl being adapted to make ratcheting engagement with the formations on the rigid ratchet element, wherein the pawl is resiliently biased against the formations on the rigid ratchet element, and wherein the pawl comprises three or more pawl members resiliently biased against the rigid ratchet element at regular intervals along the length of the rigid ratchet element, the pawl members forming pairs, the axial distance between each successive pair of pawl members being different to the axial distance between successive formations; and

(f) a gas generator located within the housing and operable to generate gas to expand a chamber, the member being in transmission relation to the chamber, whereby the member is driven by the movement of the chamber to advance the mechanism and thereby drive the drug from the reservoir in the series of fixed increments, each of the fixed increments corresponding to a respective advancement of the mechanism.

2. The drug delivery device according to claim 1 , wherein the distance between successive formations is given by the number of pawl members multiplied by the distance between each successive pair of pawl members.

3. A drug delivery device comprising:

(a) a housing containing a drug reservoir;

(b) a slidable piston operable to expel drug from the drug reservoir;

(c) a mechanism in communication with the piston, the mechanism being operable to undergo incremental advancement and thereby drive the drug from the reservoir in a series of fixed increments, wherein the mechanism comprises a rigid ratchet element having regularly spaced formations on a surface thereof;

(d) a member operatively associated with the mechanism to cause the incremental advancement of the mechanism as the member moves in a first direction;

(e) a pawl carried on the member, the pawl being adapted to make ratcheting engagement with the formations on the rigid ratchet element, wherein the pawl is resiliently biased against the formations on the rigid ratchet element, and wherein the pawl comprises three or more pawl members resiliently biased against the rigid ratchet element at regular intervals along the length of the rigid ratchet element, the pawl members forming pairs, the axial distance between each successive pair of pawl members being different to the axial distance between successive formations; and

(f) a gas generator located within the housing and operable to generate gas to expand a chamber, the member being in transmission relation to the chamber, whereby the member is driven by the movement of the chamber to advance the mechanism and thereby drive the drug from the reservoir in the series of fixed increments, each of the fixed increments corresponding to a respective advancement of the mechanism, the device further comprising means for manually adjusting the delivery rate.

4. The drug delivery device according to claim 3 , wherein the member reciprocates to cause the incremental advancement of the mechanism and the means for manually adjusting the delivery rate comprises means for limiting the travel of the member, whereby the volume of drug delivered on each reciprocating stroke is controllable.

5. The drug delivery device according to claim 3 , wherein the means for manually adjusting the delivery rate comprises means for delivering a bolus dose of drug.

6. The drug delivery device according to claim 5 , wherein the means for delivering a bolus dose of drug comprises means for manually advancing the mechanism by one or more steps independently of the gas generating mechanism.

7. The drug delivery device according to claim 6 wherein the means for manually advancing the mechanism comprises means for manually advancing the lever extending between the chamber and the mechanism, operable from the exterior of the housing.

8. The drug delivery device according to claim 7 , wherein the mechanism comprises a ratchet and wherein the means for manually advancing the mechanism comprises a pawl which is manually reciprocable from the exterior of the housing.

9. A method of delivering drug to a patient comprising the steps of:

(a) affixing a drug delivery device to the surface of the patient's skin, the drug delivery device comprising:

(i) a housing suitable for receiving a drug reservoir;

(ii) a piston slidably supported in the housing and operable to expel drug from the drug reservoir;

(iii) a mechanism in communication with the piston, the mechanism being operable in cycles to drive the drug from the reservoir in a series of fixed increments;

(iv) a member operatively associated with the mechanism to start the cyclical operation of the mechanism as the member moves in a first direction; and

(v) a gas generator located within the housing and operable to generate gas to expand a chamber, the member being in transmission relation to the chamber;

(b) adding a drug reservoir to the housing; and

(c) activating the device whereby the member is driven by the movement of the chamber to cycle the mechanism and thereby drive the drug from the reservoir in the series of fixed increments, each of the fixed increments corresponding to a respective cycle of the mechanism,

wherein means are provided for advancing the mechanism manually.

10. The method according to claim 9 , wherein the method further comprises the step of manually advancing the mechanism to deliver a bolus dose of drug to the patient.

Assignments (8)